Laser Engraver / Cutter build log - part 1

After a week of experimenting I have made some decisions with my laser engraver but I still have a lot left to decide.

I am going to publish regular video updates for this project, the first of which is below.

I have decided to use threaded rod for the z and y axis drive shafts and I have come up with a solution for the nut backlash that goes along with this.
I have changed my plans for the overall shape and simplified the design down to something that seems strong yet easy to fabricate.